Gill
Please make sure that you have reviewed the criteria for the Support Group and that you can reasonably show that you now meet one or more of these Descriptors, our ESA Claim has a list of these. A worsened condition does not always mean that you will qualify.
Be aware, reporting a Change will result in a new ESA50 being issued and you will almost certainly require a face to face assessment, the new Decision, whatever it is, will supersede your existing award.
If you are happy to go ahead then write to the DWP office managing your claim notifying them of the deterioration and asking to be reassessed, if you can afford it and obviously are able to get to a Post Office, use a Tracked Post so that you have proof of delivery, the date of your letter should be used as the start date for any new award.
You can make a new claim for PIP, our PIP Claim guide explains the process and how to contact the DWP.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems